1. Field of the Invention
The invention is directed to using engine cooling air to pneumatically blast dust, chaff and other debris off the top of an axial separator.
2. Description of the Prior Art
In threshing a harvested crop, the grain is separated from straw and chaff and deposited into a holding tank. With conventional combines the harvested crop is directed to a transversely mounted threshing cylinder and concave, which threshes the crop separating the grain from straw. The residue is then directed to a beater further separating the grain from straw. The straw residue is then passed over oscillating apertured straw walkers which direct the straw out of the back of the combine while allowing additional grain to fall through the apertures. Grain and chaff falling from the threshing concave and straw walkers is directed to a cleaning shoe for separating the chaff from the grain. A blower assembly is used in this final step to blow the lighter chaff away from the heavier grain.
In an axial flow combine, the grain is directed to a cylindrical tube housing a rotor. The harvested crop is threshed and separated in the cylindrical tube with the grain and chaff falling therefrom in a manner similar to the conventional combine. Case International of Raoine, Wis. currently markets and manufactures a axial flow combine having a single rotor. Ford New Holland of New Holland, Pa. currently markets and manufactures an axial flow combine having a pair of rotors mounted side-by-side.
A hybrid machine having a transverse threshing cylinder and a pair axial separating units is disclosed in U.S. Pat. No. 4,739,773. The axial separating units comprise cylindrical tubes having rotors housed therein. It has been found that dust, chaff and other debris collects on the top of the axial separating units.